The fundraising is limited to major institutions and not private investors.

Analysts said Tesla’s ability to raise more than $1.5bn indicated an appetite for risk among investors, as low interest rates have limited returns in many other types of investments. High stock market valuations have also made it harder to make a profit.

“Without the proceeds from the note offering, Tesla’s liquidity position would be stressed,” analysts at Moody’s said, warning of risks to potential investors.

Tesla had about $3bn in cash at the end of June, but it spent more than $2bn in the most recent quarter.

The company founded by Elon Musk has frequently turned to investors to overcome persistent operating losses.

Tesla plans to eventually make more than 500,000 of the new Model 3 cars a year at its Fremont factory – or about 10,000 per week.

Moody’s said the target was ambitious given the relatively small size of the US electric car market.